I've got an A1 style Fulton Armory Legacy Rifle. It was my first AR and I ordered it with a C7 upper to get as close as I could to an A1 in a new rifle. Since then, I've built a couple ARs and am building a more authentic A1-style rifle. I've got a Colt M16A1 upper from CDNN. If Colt-653's A1 lower deal ever comes together, I'll put it on one of those. If not, I'll modify a Stag/CMT lower to A1 specs (or as close as possible).
Once I have a more authentic A1 clone, I plan to turn my Legacy Rifle into my SHTF gun. I'd like to put Surefire M511 handguards, a Colt CS stock (if I can find one for less than SAW wants) and RB Precision aluminum buttplate on. It's got a Colt USGI 1x12 barrel and a Colt bolt and carrier. I've already upgraded the extractor and ejector springs and bolt rings and polished the chamber. There's not much more I can do with the internals. The rifle is broken-in, shoots close to MOA at 100 yards and is dead reliable with XM193 or Q3131A and USGI 20s and 30s.